As electrical equipment in the shape of a flat panel, there is, for example, a display device 101 of a wall-mounted television 110 situated on a wall surface. In the wall-mounted television 110, as shown in FIGS. 6 and 7, an additional device 102, which includes a communication control unit 102b for processing video signals to be displayed on the display device 101 and a power supply unit 102a for the display device 101, is disposed in a recessed box SB embedded in a wall panel WP so as to prevent the display device 101 from protruding far from the wall surface. Drive power is fed into the display device 101 through a power line 103 connected between the additional device 102 and a rear surface of the display device 101. Electrical signals such as the video signals are outputted to the display device 101 through signal lines 104 (Patent Literature 1).
Such a wall-mounted television 110 attached to the wall surface requires boring a hole in the wall panel WP to contain the additional device 102 in the recessed box SB embedded in the wall panel WP. Since the wall panel WP requires working and the hole limits the position of attachment, the wall-mounted television 110 cannot be moved to a desired position. Thus, a set top box STB for outputting video signals and control signals to the display device is separated from the display device, and the set top box STB and the display device are connected with cables or wireless communications as described in Patent Literature 2. This facilitates slimming of the display device, i.e., the flat panel-shaped electrical equipment, and allows the display device to be disposed in an arbitrary position.